This type of protective bag for cards and the like is, in general, formed into a rectangular shape from transparent synthetic resin film such as polyvinyl chloride film and used as protective bags through which character designs or letters printed on cards or the like such as character cards, playing cards, name tags, payment or other slips, vouchers, and various leaflets can be seen. Those protective bags for cards and the like are used, with an adhesive applied to its outer surface, also as a head part of a file or the like or as a card-holding pocket on the back cover of a product catalog or the like, and others.
Recently, there have been being enthusiastically played competition-type trading card games in which, with a collection of character cards having Pokémon (registered trademark) or other popular characters printed thereon and further having circular arc-shaped four corners, one card in the highest position is extracted and presented out of the player's own stacked cards one by one for use in play.
Under such circumstances, conventional protective bags, having right-angled edges at the four corners, have suffered a difficulty that when in use, particularly in an operation of cutting cards, which is so called shuffle, the player feels a pain at the hands due to those sharp edges. Moreover, those protective bags do not fit the cards in terms of shape, causing misalignment of the cards within the protective bag or other results. Thus, the player cannot get a feeling of using the cards themselves, leading to a problem of poor handleability.
This being the case, some players privately cut and remove corner portions of the protective bag in conformity to the shape of the cards or the like by a corner cutter or the like so that right-angled edges of the protective bag are formed into circular arc-shaped ones. Unfortunately when the cards or the like within the protective bag are exposed outside due to the removal of the corner portions, it follows not only that the corner portions of the cards or the like become more easily breakable but also that oils and sweats of the hand adhere to the cards or the like and moreover, for example, refuse, dust and the like enter the protective bag, causing the cards or the like to be contaminated as further problems. Improvements in these aspects have been desired heretofore.
A related art of PTL 1 is known as a conventional protective bag for cards and the like. This protective bag H, as shown in FIG. 7, indeed has outer edges 101 of its base corner portions cut each into a circular-arc shape with the result that no sharp edges are included in the bag. However, because inner edges 102 of the base corner portions are angled, it would be the case that the inner edges 102 of the base corner portions in the protective bag H and circular arc-shaped outer edges of the cards or the like do not fit each other in the protective bag H.
Also in the protective bag H, a base-part sealed portion 103 and side-part sealed portions 104 are provided with a large width, giving rise to a large difference in size between the protective bag H and the cards or the like to be contained therein. Thus, the protective bag H has been unfit for playing of games as it remains in use with the cards or the like therein.